10_Integumentary System and Lymphatic System Flashcards
What is the integumentary system?
The integumentary system includes the skin and its accessory structures.
What is the largest organ of the human body?
The skin.
What are the three main layers of the skin?
- Epidermis
- Dermis
- Subcutaneous / adipose layer
What type of tissue forms the epidermis?
Epithelial tissue.
What is the primary function of keratinocytes?
To protect from heat, microbes, and chemicals.
What pigment do melanocytes produce?
Melanin.
What are the two types of melanin found in skin?
- Eumelanin (brown/black)
- Pheomelanin (reddish/yellow)
What is the function of Langerhans cells?
Involved in skin ‘surveillance’ as immune cells.
What are fingerprints and how are they formed?
Ridges formed during the third month of fetal development, unique to each individual.
What is the stratum corneum?
The most superficial layer of the epidermis, consisting of 25-30 layers of flattened dead keratinocytes.
How long does it take to completely replace the epidermis?
Approximately 40 days.
What causes skin color variations?
Varying degrees of melanin produced by melanocytes.
What is the primary function of the dermis?
To provide structure and support to the skin.
What components are found in the dermis?
- Collagen and elastic fibers
- Blood vessels
- Lymph vessels
- Sensory nerve endings
- Accessory structures (sweat glands, hairs, sebaceous glands)
What is the role of sebaceous glands?
To secrete sebum, which keeps hair soft and provides waterproofing for the skin.
What are the primary functions of the skin?
- Protection
- Thermoregulation
- Vitamin D production
- Sensation
- Absorption
- Excretion
How does the skin protect against dehydration?
By providing a physical barrier with closely-packed keratinized cells and melanin.
What is thermoregulation?
The process by which the skin helps maintain normal body temperature.
What happens during vasodilation?
Peripheral blood vessels widen to promote heat loss.
What is hypothermia?
When core temperature drops below 35°C.
What is hyperthermia?
When core temperature elevates above 38.5°C.
What role does UV light play in vitamin D formation?
Activates a vitamin D precursor in the skin.
What is the function of the epidermal growth factor in wound healing?
Causes multiplication of basal cells until the gap is filled.
What are the two types of scar tissue?
- Hypertrophic scar
- Keloid scar
What is a papule?
A small, firm, elevated lesion without visible fluid.
What defines a macule?
A small, flat, circumscribed lesion of a different color to normal skin.
What is a pustule?
An elevated lesion containing pus.
What is lichenification?
Thick, dry, rough plaques of thickened skin typically associated with chronic eczema.
What is erosion in terms of skin lesions?
A shallow, moist cavity in the epidermis due to wearing away.
What is the primary role of sweat glands?
To regulate body temperature and excrete waste.
What type of muscle is the arrector pili?
Smooth muscle that elevates the hair follicle.
What is lichenification?
Thick, dry, rough plaques of thickened skin with a bark-like appearance
It is the hallmark of chronic eczema or dermatitis and results from excessive scratching.
Define erosion in the context of skin lesions.
A shallow, moist cavity in the epidermis due to the wearing away of superficial epidermis
This can occur from chemicals, friction, or pressure.
What characterizes a keloid?
Raised, irregular mass of collagen due to scar tissue formation
It grows beyond the skin boundary and has strong genetic links.
What are comedones in acne?
Blackheads, whiteheads, or red bumps formed by excess sebum, keratin, and debris
Open comedo (blackhead) is oxidized oil; closed comedo (whitehead) is covered by skin.
What are the signs and symptoms of eczema/dermatitis?
Flaky, dry, oedematous, erythematous, pruritic, crusty, weepy lesions mostly on flexor surfaces of joints
Secondary bacterial infections are common complications.
What is contact dermatitis?
Acute inflammation of the skin caused by direct contact with an agent
It can be irritant (80%) or allergen (20%) contact dermatitis.
What is irritant contact dermatitis?
A non-specific inflammatory reaction to a substance contacting the skin
Often caused by abrasive chemicals that corrode the epidermis.
What characterizes allergen contact dermatitis?
A Type IV delayed hypersensitivity reaction with pruritic, erythematous rash at the site of exposure
Sensitization occurs on first exposure.
What are common allergens associated with atopic dermatitis?
- Foods (milk, eggs, soy, wheat, peanuts, fish)
- Airborne (dust mites, moulds, pollen)
Family history of atopic disorders is common in cases.
What is urticaria?
An itchy, red, blotchy, and raised rash resulting from swelling of the superficial skin
It can cause swelling in the throat and obstruction of airways.
What causes psoriasis?
Autoimmune T-Lymphocyte mediated hyperproliferation of keratinocytes
Environmental, genetic, and immunologic factors also contribute.
What are the main signs and symptoms of psoriasis?
Red scaly plaques covered with silvery shiny scales, possibly bleeding
Typically affects extensor surfaces and may include tiny dents in nails.
What triggers acne vulgaris?
- Blockage of sebaceous/hair follicle duct
- Hormonal changes, especially during puberty
Environmental factors, particularly diet, also play a significant role.
What is acne rosacea?
Chronic inflammation of the skin associated with vascular changes resulting in flushing
More common in women and often accompanied by seborrhoea.
What are the treatment options for warts?
- Allopathic: Laser or freezing
- Alternative: Antiviral herbs (e.g., thuja, olive leaf)
Warts are benign proliferations caused by Human Papillomavirus.
What is vitiligo?
Loss of skin pigmentation due to the loss of melanocytes
It is not contagious and may have a genetic or autoimmune link.
What are the classifications of burns?
- 1st degree: Affects the epidermis
- 2nd degree: All of epidermis and some dermis
- 3rd degree: Extends into subcutaneous tissue
- 4th degree: Extends into muscles and tendons
Each degree varies in severity and depth of tissue damage.
What are the functions of the lymphatic system?
- Return proteins, lipids, and water from interstitial fluid to the blood
- Provide immunity against harmful organisms
The system consists of lymph fluid and vessels that resemble veins.
What do lymphatic vessels ultimately drain into?
Thoracic duct or the right lymphatic duct
List two functions of the lymphatic system.
- Return proteins, lipids, and water from interstitial fluid to blood
- Immunity against harmful organisms
How do lymphatic vessels resemble veins?
They have thinner walls and more valves
What components make up the lymphatic system?
- Lymph fluid (lymph)
- Lymph vessels
- Lymph nodes
- Lymph organs (spleen and thymus)
- Lymphoid tissue (e.g., tonsils)
- Bone marrow
What is lymph?
A watery fluid similar to blood plasma but with less plasma proteins
What does lymph contain?
- Water
- Leukocytes
- Plasma proteins
- Fats absorbed from the small intestine
- Bacteria and cell debris from damaged tissue
Where are lymphatic capillaries located?
In spaces between cells
What is a lacteal?
A blind-ended lymph vessel in the small intestine
What are the differences between the lymphatic system and the cardiovascular system?
- The cardiovascular system is circular and closed
- The lymphatic system is linear and drains lymphatic fluid
What is the function of lymph nodes?
Filter lymph and remove foreign matter such as microbes, cell debris, and tumour cells
How many lymph nodes are generally found in the human body?
Approximately 600
How does lymph enter the lymph nodes?
Via afferent vessels
What cells are found in lymph nodes?
- Lymphocytes
- Phagocytes
What happens to lymph nodes during infection?
They can swell due to incomplete phagocytosis of microbes, known as lymphadenopathy
What is the spleen’s role in the body?
It is involved in haematopoiesis, acts as a blood reservoir, and performs phagocytosis of worn-out erythrocytes
What are the two types of pulp found in the spleen?
- White pulp
- Red pulp
What does the thymus produce that is crucial for T-Lymphocyte maturation?
Thymosin
What does MALT stand for?
Mucosa Associated Lymphoid Tissue
What is the function of lacteals?
Absorb fat-soluble substances/nutrients from the small intestines
What is lymphangitis?
Inflammation of the lymph vessels
What are the signs and symptoms of lymphangitis?
- Swelling
- Painful red lines below skin surface
- Fever
- Malaise
- Muscle ache
- Low appetite
What is lymphoedema?
Localized lymphatic fluid retention associated with a compromised lymphatic system
What is lymphadenitis?
Inflammation of lymph nodes
What is splenomegaly?
Enlargement of the spleen due to increased workload
List two causes of splenomegaly.
- Viral infections
- Liver diseases
What are two symptoms of splenomegaly?
- Abdominal pain
- Early satiety
What lifestyle changes can optimize lymphatic health?
- Regular exercise
- High anti-inflammatory and antioxidant diet
- Reducing oxidative stress
True or False: The lymphatic system returns all interstitial fluid back to the bloodstream.
False
Fill in the blank: The lymphatic system is responsible for _______.
draining and recirculating extra fluid
